CVE-2023-29465 in FlintQS
Summary
by MITRE • 04/06/2023
SageMath FlintQS 1.0 relies on pathnames under TMPDIR (typically world-writable), which (for example) allows a local user to overwrite files with the privileges of a different user (who is running FlintQS).
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Analysis
by VulDB Data Team • 12/10/2025
CVE-2023-29465 represents a critical path traversal and privilege escalation vulnerability affecting SageMath FlintQS 1.0, a library used for integer factorization operations. This vulnerability stems from the software's improper handling of temporary file creation within the TMPDIR directory, which is typically world-writable by design to allow multiple users to create temporary files. The flaw allows local attackers to manipulate the temporary file creation process and overwrite files that belong to other users who are running FlintQS processes, creating a significant security risk in multi-user environments.
The technical implementation of this vulnerability involves the use of predictable temporary file names and the lack of proper file access controls during temporary file creation. When FlintQS generates temporary files, it does not adequately secure these files against manipulation by unauthorized users. The TMPDIR environment variable typically points to directories like /tmp or /var/tmp that are accessible to all users on the system. Attackers can exploit this by creating symbolic links or by directly overwriting files in the temporary directory with malicious content that will be processed by the privileged FlintQS process.
This vulnerability directly maps to CWE-377: Insecure Temporary File and CWE-276: Incorrect Permissions, as it demonstrates poor handling of temporary file creation and inadequate permission management for temporary resources. The operational impact is severe as it allows for privilege escalation attacks where a low-privilege user can effectively execute arbitrary code with the privileges of the user running the FlintQS process. In environments where FlintQS is used for cryptographic operations or mathematical computations that require elevated privileges, this creates a potential pathway for attackers to compromise system integrity and confidentiality.
The attack vector requires local system access and involves careful timing and manipulation of the temporary file creation process. An attacker must be able to write to the TMPDIR location while the target process is running, which typically involves creating a race condition or directly overwriting files that will be accessed by the privileged process. This vulnerability is particularly concerning in shared computing environments or systems where multiple users have access to the same temporary directories, as it can be exploited to gain unauthorized access to sensitive operations and data. The security implications extend beyond simple file overwrites to potentially allow for complete system compromise when combined with other attack vectors.
Mitigation strategies should focus on implementing proper temporary file handling practices including the use of secure temporary file creation functions, setting appropriate file permissions, and avoiding predictable temporary file names. The recommended approach involves using system calls that create temporary files with exclusive access rights, such as mkstemp() or similar secure functions that prevent symbolic link attacks. Organizations should also consider restricting access to TMPDIR locations, implementing proper file access controls, and regularly auditing temporary file usage patterns. Additionally, system administrators should ensure that the FlintQS library is updated to versions that address this vulnerability and implement monitoring for unusual temporary file creation patterns that might indicate exploitation attempts. The vulnerability highlights the importance of following secure coding practices and adheres to the principle of least privilege, where temporary files should never be created with world-writable permissions in security-sensitive contexts.